Almost 100 years ago it was recognized that breast cancer exhibited a degree of hormone dependency. Disease regression was achieved through estrogen ablation.
Studies of normal breast tissue indicate that endogenous hormones of the menstrual cycle influence rates of cell division and cell death. Speroff, The Breast, in: Speroff, Ed., Clinical Gynecologic Endocrinology & Infertility, Fourth Edition, Baltimore Williams & Williams: 1989: 629:91-119. Estrogen levels rise sharply and then fall in the absence of progesterone during the follicular phase of the cycle. Following ovulation, levels of these hormones increase and then decline before the onset of menses. The pattern of cyclic hormone concentration has been shown to influence both immune parameters and growth factors.
Laboratory studies have revealed that estrogen influences the growth fraction of human breast adenocarcinomics. When both estrogen and progesterone are present, this growth factor is significantly depressed. Jones, Influence of Steroid Hormones on the Growth Fraction of Human Breast Carcinomas, Am. J. Clin. Pathol. 1987, 88:132-138, Retardation of human breast cancer cells in the presence of progesterone has also been observed.
Cancer cells may be released into the circulation during surgery or other invasive procedures. It has therefore been suggested that a short, preoperative course of tamoxifen may be beneficial. McGuire, The Optical Timing of Mastectomy: Low Tide or High Tide?, Ann. Intern. Med. 1991, 115:401-403, Editorial. Some clinicians have proposed administering progesterone at the time of surgery to enhance prognosis by interrupting metastatic seeding.
The present invention contemplates the acute administration of a GnRH analog (or mime) as a pretreatment to invasive procedures such as surgery for breast, prostate or other cancers in order to decrease the reoccurrence rate. Administration results in the suppression of gonadal steroid dependent growth factors and neovascular processes that contribute to metastasis or recurrence in situ.
It is accordingly the object of the present invention to provide an adjunctive method to be employed in conjunction with the excisement of a neoplasm, cysts or portion thereof. This and other objects of the present invention will become apparent to those of ordinary skill in this from the following detailed description.